A search engine is an information retrieval system that is designed to help users find information. Search engines help to minimize the time required to find information of interest and the amount of information which must be consulted. The most popular form of search engine is a Web search engine that searches for information on the public World Wide Web. Other kinds of search engines include enterprise search engines, which can search for information stored in, for example, records in one or more databases on an intranet.
Search engines provide a search interface for users to specify search criteria. Search engines identify data objects (e.g., documents, database records, etc.) that contain information that match the specified search criteria. Word searching is the most popular form of search, and a search match occurs when a data object contains a word or words that are specified in a user query. The method or apparatus will be described with reference to word searching, it being understood that the claims below should not be limited thereto.
There are several varieties of syntax in which a search engine user can express a query. Some methods are formalized and require a strict, logical and algebraic syntax. The query can be quite simple, a single word at minimum. Building a more complex query may require the use of Boolean operators (e.g., AND, OR, NOT, etc.) that allow a user to refine and extend the terms of the search. Other approaches are less strict and allow for a less defined query.